WGUl D425l Pre-l Assessmentl V1l (Latestl
2026/l 2027l Update)l Introductionl tol
Chemistry|l 100%l Verifiedl Questionsl &l
Answersl |l Gradel A
Q:l Whichl terml isl usedl tol describel atomsl thatl havel thel samel atomicl numberl butl
differentl massl numbersl becausel ofl varyingl numbersl ofl neutrons?
Answer:
Isotopes
Q:l Whatl isl thel atomicl massl unitl (amu)l ofl al proton?
Answer:
1l amu
Q:l Brominel (Br)l hasl twol naturallyl occurringl isotopes:l bromine-79l atl 50.69%l withl anl
atomicl massl ofl 78.918l amu,l andl bromine-81l atl 49.31%l withl anl atomicl massl ofl 80.916l
amu.l
Whatl isl thel averagel atomicl massl ofl bromine?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
79.90l amu
,Q:l Naturallyl occurringl zirconiuml (Zr)l isl composedl ofl 51.45%l ofl zirconium-90l
(89.905l amu),l 11.22%l ofl zirconium-91l (90.906l amu),l 17.15%l ofl zirconium-92l (91.905l
amu),l 17.38%l ofl zirconium-94l (93.906l amu),l andl 2.800%l ofl zirconium-96l (94.908l
amu).l
Whatl isl thel averagel atomicl massl ofl zirconium?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
91.20l amu
Q:l Chlorinel (Cl)l hasl twol naturallyl occurringl isotopes:l chlorine-35l atl 75.77%l withl anl
atomicl massl ofl 34.969l amul andl chlorine-37l atl 24.23%l withl anl atomicl massl ofl 36.966l
amu.
Whatl isl thel averagel atomicl massl ofl chlorine?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
35.45l amu
Q:l Reviewl thel followingl graphl whichl showsl elementsl inl Groupl 1.
Whatl isl thel relationshipl betweenl atomicl radiusl andl electronl affinity?
, Answer:
Theyl arel inverselyl related.
Q:l Reviewl thel informationl inl thel followingl graph,l whichl showsl elementsl inl periodl 2.
Whatl isl thel relationshipl betweenl thel ionizationl energyl andl thel atomicl numbersl forl
elementsl inl periodl 2?
2026/l 2027l Update)l Introductionl tol
Chemistry|l 100%l Verifiedl Questionsl &l
Answersl |l Gradel A
Q:l Whichl terml isl usedl tol describel atomsl thatl havel thel samel atomicl numberl butl
differentl massl numbersl becausel ofl varyingl numbersl ofl neutrons?
Answer:
Isotopes
Q:l Whatl isl thel atomicl massl unitl (amu)l ofl al proton?
Answer:
1l amu
Q:l Brominel (Br)l hasl twol naturallyl occurringl isotopes:l bromine-79l atl 50.69%l withl anl
atomicl massl ofl 78.918l amu,l andl bromine-81l atl 49.31%l withl anl atomicl massl ofl 80.916l
amu.l
Whatl isl thel averagel atomicl massl ofl bromine?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
79.90l amu
,Q:l Naturallyl occurringl zirconiuml (Zr)l isl composedl ofl 51.45%l ofl zirconium-90l
(89.905l amu),l 11.22%l ofl zirconium-91l (90.906l amu),l 17.15%l ofl zirconium-92l (91.905l
amu),l 17.38%l ofl zirconium-94l (93.906l amu),l andl 2.800%l ofl zirconium-96l (94.908l
amu).l
Whatl isl thel averagel atomicl massl ofl zirconium?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
91.20l amu
Q:l Chlorinel (Cl)l hasl twol naturallyl occurringl isotopes:l chlorine-35l atl 75.77%l withl anl
atomicl massl ofl 34.969l amul andl chlorine-37l atl 24.23%l withl anl atomicl massl ofl 36.966l
amu.
Whatl isl thel averagel atomicl massl ofl chlorine?l Usel thel appropriatel numberl ofl
significantl figures.
Answer:
35.45l amu
Q:l Reviewl thel followingl graphl whichl showsl elementsl inl Groupl 1.
Whatl isl thel relationshipl betweenl atomicl radiusl andl electronl affinity?
, Answer:
Theyl arel inverselyl related.
Q:l Reviewl thel informationl inl thel followingl graph,l whichl showsl elementsl inl periodl 2.
Whatl isl thel relationshipl betweenl thel ionizationl energyl andl thel atomicl numbersl forl
elementsl inl periodl 2?
